[Basic calcium phosphate crystal deposition disease].

Hydroxyapatite crystals are a common cause of periarticular disease. Virtually, any joint can be involved, but the shoulder is by far most commonly involved. These calcifications, often asymptomatic, can lead to an acute microcrystalline tendinitis or bursitis, which may simulate infection. The diagnosis of periarticular calcifications relies on imaging techniques using X-rays or ultrasounds. Treatment of acute tendinitis or bursitis includes icing, rest, analgesics or non steroidal anti-inflammatory drug and oral steroids or local steroids injection. Removal of the deposit can be considered in patients with chronic pain, particularly at the shoulder.